1. Field of the Invention
The present invention relates to an impact energy absorbing device provided in the passenger compartment of a vehicle for protecting an occupant or occupants from injury caused by impact in a collision or other vehicle accident, and particularly to improvements in a knee protecting device for the occupant of the vehicle, wherein a knee pad is disposed between protrusions formed in the passenger compartment of the vehicle and the knees of the occupant.
2. Description of the Prior Art
A gas bag device has been developed for buffering impacts on the driver of the vehicle in a collision or other vehicle accident. This device is adapted to expand the gas bag to restrain the driver in a collision or other vehicle accident, thereby protecting the driver. If a vehicle equipped with this gas bag is involved in a collision or other vehicle accident, the head, chest and the like of the driver will be satisfactorily protected by the gas bag. However, the knees of the driver strike the lower portion of the instrument panel. Consequently, a knee pad is frequently provided close to the position where the knees strike the lower portion of the instrument panel so that impact energy acting on the knees is absorbed.
However, with the conventional knee protecting device wherein only the knee pad is disposed between the protrusions in the passenger compartment and the knees of the driver, the knees of the driver, directly opposed to the hard protrusions in the passenger compartment such as a steering column tube or a breakaway bracket, are not satisfactorily protected. In a vehicle having a steering wheel on the left side, the right knee of the driver is further from the column tube and breakaway bracket, and hence, the impact load on that knee is low, so that satisfactory protective performance for the knee can be obtained with a knee protecting device like a conventional one. However, the left knee is very close to the aforesaid column tube and breakaway bracket and directly opposed thereto, and hence, the knee protecting device is required to have high protective performance for that knee. In order to improve the impact absorbing performance of the knee pad, efforts have been made to increase the thickness of the knee pad or to soften the knee pad by slitting it or the like. With the former method, i.e., increasing the thickness of the knee pad, movement of the left knee of the driver is restrained. As a result, driving is hindered and it is difficult for the driver to get into and out of the vehicle. Additionally, with the latter method, i.e., softening the knee pad, for the right knee, impact energy can be satisfactorily absorbed because the amount of deflection of the knee pad can be allowed to be high. However, for the left knee, which can directly strike the breakaway bracket and the like, a heavy load can be placed on that knee and the driver cannot be satisfactorily protected because the amount of allowable deflection of the knee pad on that side is only slight. The allowable deflection on that side is less than that on the right side.